Biology subjects

Korol, A.

Publications and source records attributed to Korol, A..

3 recordsLinked to original sources

bioRxiv2023

Allelic variation in the wheat homolog of topoisomerase II is associated with crossover rate

Meiotic recombination is a fundamental biological process that impacts genetic diversity and response of variants to selection. The increase in crossover (CO) frequency by modulating the activity of meiotic genes has been suggested as potential means to improve the efficiency of selection and mitigate the negative impact of linkage drag in crop improvement programs. In this study, we used the wheat nested association mapping (NAM) population to map QTL associated with CO rate and harboring TaTOPII-A1, a gene encoding topoisomerase II that is involved in the regulation of meiosis. An amino acid changing SNP (T/C) located in exon 19 of TaTOPII-A1 with a predicted functional effect showed an association with CO rate. The T-allele of TaTOPII-A1 was associated with a statistically significant 5.9 % increase in COs across several NAM families. The involvement of TaTOPII-A1 in processes affecting CO rate in wheat was confirmed using a TaTOPII-A1 mutant. A strong-effect missense mutation in the TaTOPII-A1 coding region resulted in 1.4-fold increase in the genetic map length and 53% increase in CO rate compared to the wild-type allele. These results demonstrate that functional mutations in TaTOPII-A1 can lead to increased CO frequency. The mutant and natural alleles of TaTOPII-A1 identified in our study could serve as new sources of recombination-promoting genes to manipulate CO rate in wheat and possibly other crops.

genetics↗

bioRxiv2021

Shift-inducible increase in recombination rate as an evolving strategy in a periodic environment: a numerical model

Numerous empirical studies have witnessed a plastic increase in meiotic recombination rate in organisms experiencing physiological stress due to unfavourable environmental conditions. Yet, it is not clear enough which characteristics of an ecological factor (intensity, duration, variability, etc.) make it stressogenic and therefore recombinogenic for an organism. Several previous theoretical models proceeded from the assumption that organisms increase their recombination rate when the environment becomes more severe, and demonstrated the evolutionary advantage of such recombination strategy. Here we explore another stress-associated recombination strategy, implying a reversible increase in recombination rate each time when the environment alternates. We allow such plastic changes in the organisms, grown in an environment different from that of their parents, and, optionally, also in their offspring. We show that such shift-inducible recombination is always favoured over intermediate constant optimal recombination. Besides, it sometimes outcompetes also zero and free optimal constant recombination, therefore making selection on recombination less polarized. Shift-inducible strategies with a longer, transgenerational plastic effect, are favoured under slightly stronger selection and longer period. These results hold for both panmixia and partial selfing, although selfing makes the dynamics of recombination modifier alleles faster. Our results suggest that epigenetic factors, presumably underlying the environmental plasticity of recombination, may play an important evolutionary role.

evolutionary biology↗

bioRxiv2018

Optical and physical mapping with local finishing enables megabase-scale resolution of agronomically important regions in the wheat genome

BackgroundNumerous scaffold-level sequences for wheat are now being released and, in this context, we report on a strategy for improving the overall assembly to a level comparable to that of the human genome.\n\nResultsUsing chromosome 7A of wheat as a model, sequence-finished megabase scale sections of this chromosome were established by combining a new independent assembly based on a BAC-based physical map, BAC pool paired end sequencing, chromosome arm specific mate-pair sequencing and Bionano optical mapping with the IWGSC RefSeq v1.0 sequence and its underlying raw data. The combined assembly results in 18 super-scaffolds across the chromosome. The value of finished genome regions is demonstrated for two approximately 2.5 Mb regions associated with yield and the grain quality phenotype of fructan carbohydrate grain levels. In addition, the 50 Mb centromere region analysis incorporates cytological data highlighting the importance of non-sequence data in the assembly of this complex genome region.\n\nConclusionsSufficient genome sequence information is shown to be now available for the wheat community to produce sequence-finished releases of each chromosome of the reference genome. The high-level completion identified that an array of seven fructosyl transferase genes underpins grain quality and yield attributes are affected by five f-box-only-protein-ubiquitin ligase domain and four root-specific lipid transfer domain genes. The completed sequence also includes the centromere.

genomics↗